Ventilators are machines used to assist or replace spontaneous breathing of a patient. In some circumstances, a ventilator may also be used to supply anesthetic agents to the patient undergoing certain medical procedures. With existing ventilators, monitoring patient breathing and ventilator performance may be difficult. A caretaker may not easily determine whether a patient is struggling to breathe, whether a patient is fighting the assistance of the ventilator or whether the ventilator is optimally operating to assist the patient with his or her breathing.